A Male Birth Control Pill? Oral Contraceptive Tested That Would 'Block The Transport Of Sperm’

Researchers are working on a male form of the birth control pill that doesn’t have long-term affects on sperm. Pictured, men wearing condom style hats watch marine traffic at the 60th Cannes Film Festival May 20, 2007. Photo: Reuters

It’s on many women’s (and men's) holiday wish lists: a male birth control pill that can be flipped on and off like a light switch when needed. According to researchers in Australia and Britain, scientists are one step closer to developing a male contraceptive pill that prevents pregnancy and doesn’t affect sexual function.

Scientists have created a contraceptive that proved successful in male mice, a new study published in the U.S. journal Proceedings of the National Academy of Science reports. The drug stops sperm movement by blocking two proteins, alpha1A-adrenoceptor and P2X1-purinoceptor, which are responsible for pushing sperm through the vas deferens during ejaculation. “This modification produced 100 percent infertility without effects on sexual behavior or function,” researchers wrote.

They noted that sperm taken from mice injected with the protein inhibitor still produced normal baby mice in artificial insemination attempts, even though the mice’s vas deferens did not contract normally when stimulated. This suggested that the protein inhibitor affected sperm movement but not the sperm itself.

“The sperm is effectively there, but the muscle is just not receiving the chemical message to move it,” Sab Ventura, lead researcher on the study, told AFP.

Compared to creating a female contraceptive pill, developing a male variety is far more difficult. Instead of stopping just one egg from becoming fertilized, a successful male contraceptive would have to stop millions of the little guys from reaching the egg.

Additionally, previous attempt to develop male birth control were often criticized for their long-term health complications, including affecting the long-term viability of sperm.

Also, meddling with sperm must be done in a way that doesn’t affect the genetics of future offspring. “In addition, a male oral contraceptive should ideally be readily reversible, and leave sexual function unaffected,” AFP noted.

That’s where researchers say they’ve got it right this time around. Instead of trying to simply block sperm, they’re blocking the transport of sperm. "This bypasses perhaps the greatest stumbling block in the quest for a socially acceptable male contraceptive," the scientists wrote.

"If you're a young guy and you get to the stage where you wanted to start fathering children, you stop taking it and everything should be okay," Ventura told ABC. "It would be like an oral medication probably taken daily just like the female contraceptive pill."

Researchers say any male birth control pill developed from their research is still 10 years down the road.